Rotary sheet metal offset printing press



Dec. 24, 1940. w. MAILANDER 2,226,315

I ROTARY SHEET METAL OFFSET PRINTING PRESS Filed July 17, 1939 Sheets-Sheet 1 I71 ver for:- M/[ZZ MaL'ZO-ze rye/er Dec. 24, 1940. I w. MAILANDER 2,226,315

ROTARY SHEET METAL OFFSET PRINTING PRESS Filed July 17,2939 4 Sheets-Sheet 2 I11 vs 12 for:

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Patented Dec. 24, 1940 UNITED STATES PATENT OFFICE Willy Mailinder, swarm-nae Cannstatt,

Germany Application July 17, 1939, Serial No. 285,012 In Germany July 19, 1938 14 Claims.

The present invention relates to a rotary oil'- set printing press for multl-colour printing on sheet metal plates, wherein the sheet metal plates are fed one after another to a series of consecutive single colour printing aggregates by means of rotating transfer-gripper systems or the like.

The essential feature of the invention resides in an arrangement which enables the sheet l metal plates, after having just been printed upon in a single colour aggregate, being fed to the next printing aggregate without the still wet impression being damaged. This is attained by reason of the fact, that guiding means are provided between the points where the printing cylinders of the second and the consecutive single colour printing units take over the sheet metal plate from the transfer-gripper system. and the points where the sheet metal plates are printed on by the rubber cylinders of the single colour printing aggregates which press the sheet metal plates down at their lateral edges.

The lateral edges of the sheet metal plates are held down by the guiding'means for a time,

2-) and then the rear edge of the sheet metal plates is held down by means of rods or fingers which are suitablyarranged and distributed over the width of the path of travel of the sheet metal plates.

30 The means for the initial holding down of the sheets or plates may be stationarily mounted rollers, tapering pins, rigidly mounted guide surfaces or the like, and they prevent a springing or flapping of the extremity of the metal 35 sheet or plate, which tends, by reason of its rigidity or stiffness and the action of centrifugal force, to draw away from the surface of the. consecutive printing cylinderL' Without such a holding-down means being provided, the -ilapping portion of the metal sheet or plate would come into contact with the rubber cloth of the rubber cylinder mounted above it, and the i still fresh impression on the metal sheet or plate would be smudged. and-the rubber cloth smeared.

In order to take the various gauges of the sheet metal plates into due consideration, thesheet or plate guiding members i. e. the conical rollers or the like, and the guide rods or fingers are mounted adiustably in respect of their printing 5U cylinders on a shaft, rotatably mounted on the frame of the press, which is adapted to be locked in any position into which it may have been rocked.

Further, care is taken to prevent the metal 55 sheet or plate end being deflected too far against the drum shaft, otherwise the travel of the sheet or plate becomes too irregular and disturbed. In order to achieve this purpose, the metal sheets or plates are also guided in the transfergripper system. These guiding means may com I sist of two cone pulleys which engage the lateral edges of the sheets during their transfer from one printing aggregate to another, if they have the tendency to spring or curl inwards.

The same result may however, also be attained ior instance by means. of abutments or stops in the rotating transfer-gripper system cooperating with the rear edge of the sheet or plate.

The guiding means are adjustable in such a manner that they can be adapted to the print- 1 ing of sheet metal plates of any dimensions. Thus, for instance, the cone pulleys may be adapted to be adjusted to various distances apart from one another in order to suit the width oi the sheet being printed at the time, '20 and the abutments or stops can be adjusted to correspond to the length oi the sheet. By these means a perfect transfer, and travel of the sheets in respect of the guiding means of the printing aggregates is assured.

In order to prevent the rear edge of the metal sheet or plate from getting too'far away from the rotating transfer-gripper system it is preferable to further provide stationary circularly bent guide members beneath .the transfergripper systems. 7 I

The object of the present invention is illustratedinthe appended drawings by way of example.

Figures 1 and 2 show a'lateral and longitudinal view of the arrangement of conical rollers, adapted to act as guides and also the guide rods or fingers. Figures 3 and 4 show a lateral and longitudinal view of guiding means designed as a. 40 guiding surface. Figures 5, 6 and 7, 8 show two constructional forms of the sheet or plate guiding arrangement of the..transier-8 ri per system, each embodiment being shewn in a side and longitudinal view.

Figures 1 and 2 illustrate the means for guiding the metal sheets a to be printed on, i. e. the means preventing the springing up of the metal sheets while traveling fromwa rotating 5o transfer-gripper system I to the following printing cylinders. I

The metal sheet a to be printed on, is taken over from the transfer gripper system i by the gripper I of the consecutive printing cylinder 2.

Guiding means 8, which press the lateral edges of the metal sheet a down, are mounted ,at both sides of the press on a shaft 5 mounted in the press frame 4. I

If the rear edge I) has passed under the guiding means 6 and has for instance reached the position shown in dot and dash lines, then the pressing down or holding down is effected by means of the rods or fingers I which are distributed along the width of travel of the sheet a.

In the constructional form of the guiding means 6 shown in Figures 1 and 2, they consist of loosely and rotatably mounted conical rollers, in place of which conical pins may be used. The Figures 3 and 4 show stationary guide surfaces, acting as guiding means 6' being mounted in the same manner as the conical rollers 5. They are curved and have the same inclination as the roller surface on the supporting side.

The guiding means 6 or 6 are adjustable. To this end a rockable arm 9 provided with a slot 8 may be provided on a shaft 5 mounted on the press frame .4. By means of this arm or lever it is possible to adjust and lock the shaft 5 by means of a screw bolt ill or the like and thus also the guiding means 6 or 6' at the de sired height at the desired distance from the cylinder 2.

The sheet metal plate guiding devices 6 and 1 function as follows:

When the metal sheet a is transferred from the transfer-gripper system i to the consecutive printing aggregate 2, the sheet or plate end 12 hangs downward at firstby reason of its weight. But as soon as the printing cylinder grippers 3 of the aggregate 2 have carried the metal sheet a slightly upwards and have fed it to the printing place or point, then the sheet or plate end I) tends to snap upwards because the rigid material does not automatically adapt itself to the contours of the printing cylinder 2. and because the centrifugal force tends to force it away from it.

Asit is however preferable not to mount the guiding means 6 or 6' too near to the printing line, the guide rods or fingers I have furthermore been provided, which take over the guiding, when the sheet or plate end bleaves the guiding means 6 or 6'. It is advisable not to mount the guiding means 6 or 6' too close to the printing line or point because the lever arm from the printing line or point to the means 6 or 6 becomes longer and consequently the pressure against the means 6 or 6 becomes smaller. Moreover the means 6 or 6' can then cause the metal sheet-or plate a to adapt itself in a better manner to the surface of the cylinder 2 at or respectively in front of the printing line or point. The guide rods' or fingers I are adjusted in respect to the printing cylinder surface in such a manner as to prevent the rear sheet or plate edge b from jumping up and to holdit down after it has been released by the guiding means 8 or 6. If the guide rods or fingers I are properly adjusted, they are only touched by the end edge of the sheet a and not by its cambered surface.

The guiding means 6 or 8' are adjusted according to the rigidity of the sheet metal in such a manner that the pressure exerted by these against. the metal sheet a does not rise too high. The sheet or plate guiding rods or fingers I are mounted correspondingly higher than the guiding means i or 6' so that the surface of the plate a, even if it bulgesslightly up at its middle and consequently rises somewhat more at its middle from the cylinder surface, does not come into contact with the fingers I.

In the case of stiff material, which exerts a considerably greater pressure on the guiding means 8 or 6', and consequently bulges up somewhat higher at the middle of the sheet, the guiding means 8 or 6 and also the rods or fingers I are arranged somewhat further away from the cylinder surface than is the case with elastic material. By reason of the fact that the guiding means Ii or 6' are mounted lower down and are consequently closer to the printing cylinder surface than the rods or fingers I, it is assured that the metal sheet or plate a is caught up, as it snaps upwards, first by the guiding means 6 or 6' and not by the rods or fingers I. Only when the sheet or plate end b has passed or nearly passed under the guiding means 6 or 6', can it press against the guiding rods or fingers I and they can thus take over the further guiding of the metal sheeta until the sheet or plate end b is so near to the printing line or point that no further guiding is required.

In order to obtain a smooth and steady travel of the metal sheet or plate a guiding means for them is'also provided in the transfer-gripper system I, which guiding device moreover prevents the sheets or plates :1 from hanging too far towards the gripper system shaft H, or prevents them being thrown with their extremity onto the consecutive aggregate by centrifugal force after they have been transferred. This guiding device can guide the sheets or plates a either at their lateral edges or at their rear edge. At the same time these guiding devices in the transfer-gripper system ensure a better and smoother transfer of the sheet or plate to the means 6.

Figures 5 and 6 show a means of guiding the sheets or. plates a at their lateral edges. This device consists of two cone pulleys I2; mounted on. the shaft H of the transfer-gripper system, and can be displaced with respect to one another so as to suit the width of the sheet orplate.

Figures 7 and 8 show a constructional form according to which the rear sheet or plate edge is supported. For this purpose abutments or stops II are provided on the shaft ll of the transfer-gripper system which can be of any suitable shape or form.

In order to avoid touching the printing surface, the abutinent or stop member i3 is bent rearwardly at its extremity and furthermore the stops can be adjusted according to the length of the sheet or plate. To this end they are rotatably mounted on the shaft ll of the transfergrlpper system. 1

In Figures 5 to 8 circular guide members I! stationarily mounted below the transfer-gripper system, (I) are also shown.

'What I claim is:

1. Rotary offset printing press for multicolor printing on sheet metal plates comprising a plurality of single color offset printing cylinder aggregates, rotary gripper means operative to convey sheets from a point of transfer on a cylinder of one printing aggregate to a point of transfer on a cylinder of the next printing asgregate, and means making contact with only edges of the sheet and operative in the path between the transfer point on said last mentioned cylinder and the printing line of the same printing aggregate for pressing the trailing end of the sheet towards the cylinder.

2. Rotary offset printing press for multicolor printing on sheet metal plates comprising a plurality of single color offset printing cylinder aggregates, rotary gripper means operative to convey sheets from a point of transfer on a cylinder of one printing aggregate to a point of transfer on a cylinder of the next printing ag gregate, and means making contact with only edges of the sheet and operative at successive stages in the path between the transfer point on said last mentioned cylinder and the printing line of the same printing aggregate for press ing the trailing end of the sheet towards the cylinder.

3. Rotary offset printing press for multi-color printing on sheet metal plates comprising a plurality of single color offset printing cylinder aggregates, rotary gripper means operative to convey sheets from a point of transfer on a cylinder of one printing aggregate to a point of transfer on a cylinder of the next printing aggregate, and means making contact with only lateral edges of the sheet and operative in the path between the transfer point on said last mentioned cylinder and the printing line of the same printing aggregate for pressing the trailing end of the sheet towards the cylinder.

4. Rotary offset printing press for multi-color I printing on sheet metal plates comprising a plurality of single color offset printing cylinder aggregates, rotary gripper means operative to convey sheets from a point of transfer on a. cylinder of one printing aggregate to a point of transfer on a cylinder of the next printing aggregate, means making contact with only lateral edges of the sheet and operative in thepath between the transfer point on said last mentioned cylinder and the printing line of the same printing aggregate for pressing the trailing end of thesheet towards the cylinder, and additional means making contact only with the rear edge of the sheet 5 and operative to press the trailing end of the sheet towards the cylinder at a point in the path of said sheet closer to the printing line than the place of action of the means contacting the lateral edges of said sheet. a

5. Rotary offset printing press for multi-color printing on sheet metal plates comprising a plurality of single color offset printing cylinder aggregates, rotary gripper means operative to convey sheets from a point of transfer on a cylinder 5 of one printing aggregate to a point of transfer on a cylinder of the next printing a gregat ical rollers making contact with only lateral edges of the sheet'and operative-in the path' between the transfer point on said last mentioned cylinder and the printing line of the same printingaggregate for pressing the trailing end of the sheet towards the cylinder.

6. Rotary-offset printing press for multi-color printing on sheet metal platescomprising a plurality of single color offset printing cylinder aggregates,- rotary gripper means operative to convey sheets from a point of transfer on a cylinder of one printing aggregate to a point of transfer -means with curved sheet engaging surfaces making contact with only lateral edges of the sheet and operative in the lath between the transfer point on said last mentioned cylinder and the printing line of the same printing aggregate for pressing the trailing end of the sheet towards the cylinder.

7. Rotary offset printing press for multi-color printing on sheet metal plates comprising a plurality of single color offset printing cylinder aggregates, rotary gripper means operative to convey sheets from a point of transfer on a cylinder of one printing aggregate to a point of transfer on a cylinder of the next printing aggregate, means making contact with only lateral edges of the sheet and operative in the pathbetween the transfer point on said last mentioned cylinder and the printing line of the same printing aggregate for pressing the trailing end of the sheet towards the cylinder, and a plurality of fingers making contact only with the rear edge of the sheet and operative to press the trailing the pressing means are mounted adjustably in respect to the printing cylinders on a shaft rotatably mounted in the press and having means for looking it in any position of rotation.

10. Printing press according to claim 1 in which sheet guiding means are provided in the gripper means said guide means engaging only edges of the sheet and being arranged to guide the sheet to the pressing means.

11. Printing press according to claim 2 in which sheet guiding means are provided in the gripper means said guide means engaging only edges of the sheet and being arranged to guide the sheet to the pressing means.

12. Printing press according to claim 1 in which sheet-guiding means are provided in the gripper means said guide means engaging only edges of the sheet and being arranged to guide the sheet to the pressing means, said guide means consisting of two cone pulleys rotatably coaxially wlth the gripper means and axially displaceable in respect of one another, on the conical surfaces of which rest with the lateral edges of the sheets.

13. Printing press according to claim 1 in which sheet guiding means are provided in the gripper means said guide means engaging only edges of the sheet and being arranged to guide the sheet to the pressing means, said guide means consisting of abutments rotatable co-axially with the gripper means and having rearwardly bent ends on which the rear edge of the sheet comes to lie.

14. Printing press according to claim 1 in which circularly bent guide members are statlonarily mounted below the gripper means.

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